Windows Phone Mango release candidate shipped to developers

Microsoft has released an updated version of the Windows Phone developer …

Windows Phone Mango was released to manufacturing Tuesday, with handset manufacturers and mobile network operators receiving the finalized operating system code so that they can wrap up their own development and testing efforts. On Wednesday, developers for the platform were given access to a Mango update that's almost the RTM version—but not quite.

The full release candidate SDK will ship some time in August, and for the final RTM firmware, developers will have to wait for its public release. What Microsoft is distributing in the meantime is a precursor to both: an SDK that's newer than the one released at the end of June, and a firmware that came a few builds before RTM; specifically, build 7712. RTM is build 7720. Because both the firmware and the SDK are in a weird "not quite release candidate" state, they're only available to paid-up registered developers, and have to be downloaded from the invitation-only Connect site. Every registered developer should have been invited, though developers who signed up after the first beta firmware was made available say that they have not received their invitations.

Just as with the first beta, Microsoft has no plans to allow upgrading to RTM when that becomes available. So if you're planning to install the firmware onto a handset currently using a stable firmware release, you'll have to make a backup before you can install the beta, and you'll have to restore that backup to allow upgrading to RTM. Don't lose the backup.

Microsoft has also stated what Mango will actually be called. Windows Phone 7 Product Manager Cliff Simpkins told Mary Jo Foley that the public branding will be "Windows Phone 7.5"—though the firmware itself will report its version as "7.10". Why this discrepancy exists wasn't explained.